Inherently mold-releasable mold or casting composition

ABSTRACT

An inherently mold-releasable composition which may be used as either the casting composition or, in its cured state, the mold or as a mold liner is disclosed. No additional mold release agent is necessary when using the composition herein which is prepared from (a) hydroxyl or carboxyl-terminated polymers containing pendant 3-perfluoroalkyl-2-iodopropyl or 2-perfluoroalkyl-1iodoethyl groups, and (b) polyisocyanates or polyepoxides.

United States Patent [1 1 Villa Apr. 29, 1975 INIIERENTLYMOLD-RELEASABLE MOLD OR CASTING COMPOSITION [75] Inventor: Jose L.Villa, Heightstown, NJ.

[73] Assignee: Thiokol Chemical Corporation,

Bristol, Pa.

[22] Filed: Sept. 10, 1974 [21] Appl. No.: 504,782

Related U.S. Application Data [62] Division of Ser. No. 356,976, May 3,1973, Pat. No.

[52] U.S. Cl. 260/835; 106/3825; 204/159.18; 260/75 NA; 260/77.5 CR;260/94.7 HA; 260/830 R; 260/830 S; 260/836; 260/837 R;

3,431,235 3/1969 Lubowitz 260/837 3,515,772 6/1970 Lubowitz 260/8373,576,903 4/1971 Groff 260/835 3,595,944 7/1971 Manning 260/8363,616,193 10/1971 Lubowitz.... 260/837 3,645,989 2/1972 Tandy..-260/80.73 3,645,990 2/1972 Raynolds 260/80.75 3,678,127 7/1972 Schmid260/835 3,725,374 4/1973 Mayes 260/830 3,739,041 6/1973 Schmid 260/835Primary Examiner-Paul Lieberman Attorney, Agent, or F [rm-Thomas W.Brennan [57] ABSTRACT An inherently mold-releasable composition whichmay be used as either the casting composition or, in its cured state,the mold or as a mold liner is disclosed. No additional mold releaseagent is necessary when using the composition herein which is preparedfrom (a) hydroxyl or carboxyl-terminated polymers containing pendant3-perf1uoroalkyl-2-iodopropy1 or Z-perfluoroalkyl-l-iodoethy1 groups,and (b) polyisocyanates or polyepoxides.

11 Claims, No Drawings lNI-IERENTLY MOLD-RELEASABLE MOLD OR CASTINGCOMPOSITION This is a divisional of application Ser. No. 356,976, filedMay 3, 1973, now U.S. Pat. No. 3,838,110.

BACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrelates to an inherently moldreleasable composition for use as either acasting composition or, in its cured state, a mold or a mold liner, i.e.no additional mold release agent or parting compound need be used inconjunction with this invention. The invention is a cured or curablepolymer prepared from a polyisocyanate or a polyepoxide and a hydroxylor carboxyl-terminated polymer containing pendant vinyl or allyl groupswherein perfluoroalkyl iodides have been added to said groups to formZ-perfluoroalkyl-l-iodoethy or 3-perfluoroalkyl-2- iodopropyl groups.

2. Description of the Prior Art Previous polymers containing perfluorogroups have centered upon adding the perfluoro group to a monomer andthen polymerizing the monomer to yield the desired product. Cf. U.S.Pat. Nos. 3,645,989 and 3,645,990. Whereas, in this invention theperfluoroalkyl iodide is added to the pendant vinyl or allyl groups of ahydroxyl or carboxyl-terminated polymer containing said groups.

Also, previous reactions of fluoroalkyl iodides with organic compoundshave centered about the addition of polyfluoroalkyl methyl or ethyliodides, i.e. R,CH I or R CH CH l, to low molecular weight aliphaticcompounds to yield products wherein the iodide is on a carbon atomseparated from the perfluoro group by more than one interventing carbonatom. Examples of these reactions are illustrated in the articles byHenne et al., J. Am. Chem. Soc. 73, 1791 (1951); by Hazeldine, J. Chem.Soc., London, 1199 (1953); as well as in U.S. Pat. Nos. 2,972,638,3,016,406, and 3,408,411.

Other prior work dealt with reactions of polyfluoroalkyl iodides whichwould not occur by ultraviolet light initiation. Cf. U.S. Pat. No.3,145,222. The preparation of the basic perfluoralkyl iodide modifiedhydroxyl or carboxyl-terminated polymer used in this invention mayproceed under ultraviolet light catalysis.

Additionally, U.S. Pat. No. 3,427,366 as well as other patents describethe production of polyurethanes from hydroxy terminated diene polymers,but not with fluorocarbon containing polymers. Coassigned U.S. Pat. No.3,842,053 issued Oct. 15, 1974 discloses the preparation ofperfluoroalkyl iodide modified polymeric resins which are suitable foruse herein. Also, previous fluorinated polyurethanes have had thefluorine attached directly to backbone carbon atoms as opposed to havinghigh fluorine content groups attached to pendant groups so as to becloser to the surface of the cured product which is believed to be amajor factor in the mold release properties herein.

SUMMARY OF THE INVENTION This invention provides fluorine-containingpolymers which have unusual properties and surface characteristics suchas to make the cured polymers inherently mold-releasable. Thus, a moldor mold liner prepared from these polymers requires no additional moldrelease agent. Alternatively, when these polymers are used as thecasting composition, no additional mold release agent is necessary.

It is an object of this invention to prepare polymeric molds, moldliners, and casting compositions which require no additional moldrelease agent for use as such.

These and other objects will become apparent in the followingdescription and claims.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The mold, mold liner, orcasting composition of this invention is prepared from a polymer whichis prepared from (1) a hydroxyl or carboxyl-terminated polymer havingpendant vinyl or allyl groups, wherein perfluoroalkyl iodides have beenreacted with at least some of the pendant groups and (2) apolyisocyanate or a polyepoxide. It is believed that-the unusual moldrelease properties of the resultant mold, mold liner or castingcomposition are due to the placement of the perfluoroalkyl iodide groupson the pendant vinyl or allyl groups such that the fluorocarbon chainsare effectively predominantly on the surface of the resultant curedpolymer.

Accordingly, the polymers which are suitable for use in this inventionmust have two features: l they must have hydroxyl or carboxyl terminalsto subsequently react with polyisocyanates or polyepoxides to preparethe prepolymers and (2) they must have pendant vinyl or allyl groupssuitable for reaction with the perfluoroalkyl iodides. Polymers havingthese requirements include but are not limited to hydroxyl orcarboxylterminated polybutadiene polymers and copolymers, polyethers,polyesters, and polysulfides. With all of these polymers, generally thehigher the pendant vinyl or allyl content, the more fluorine which maybe attached to the polymer.

The hydroxyl-terminated polybutadiene polymers and copolymers may beprepared in any well known manner such as in U.S. Pat. Nos. 3,427,366 or3,663,480 incorporated herein by reference. Alternatively, thesepolymers are commercially available and are sold under tradenames suchas PolyBD R-15M and R-45HT from the Atlantic Richfield Company, andHYSTL 0-1000, 0-2000, and 6-3000 from the I-Iystl Development Company.

The carboxyl-terminated polybutadiene polymers and copolymers may beprepared as described in U.S. Pat. No. 3,235,589, and may have amolecular weight within the range of 500 to 10,000. Alternatively, acommercially available carboxyl-terminated butadiene liquid polymer, asfor example, those designated HYSTL C-1000 and C-2000 from the I-lystlDevelopment Company, and those designated PIC-434 from Thiokol ChemicalCorporation, may be used.

The copolymers of butadiene may be with styrene, acrylic acid, vinylacetate, acrylonitrile, isoprene, a-methyl styrene, N-vinyl carbazole,N-vinyl pyrollidene, methacrylic acid, acrylamide, methyl methacrylate,butyl methacrylate, vinyl chloride, or any other monomer. Examples ofcommercially available copolymers are designated Poly BD CS-15 andCN-15from Atlantic Richfield Company. CS-15 is a /25 butadiene/sytrenepolymer. CN-15 is a /15 butadiene/acrylonitrile polymer.

Representative polyester resins containing pendant vinyl groups will bethose obtained from the reaction of dicarboxylic acid, with, trimethylolpropane monoallyl ether or a mixture of the allyl ether with a glycolsuch as propylene glycol.

The number of pendant vinyl groups, present in the polyester resin,would depend on the amount of the allyl ether used in theesterification.

Polyether containing pendant vinyl groups are obtained from thepolymerization of an oxirane such as allyl glycidyl ether in thepresence of boron trifluoride as the catalyst.

Other epoxidcs such as ethylene oxide can be copolymerized with theallyl glycidyl ether as a way of controling the number of pendant vinylgroups present in the polyether.

A polysulfide backboned polymer with the pendant allyl groups usefulherein may be prepared by incorporating 2,3-dichloropropylallylether inthe reaction in place of, or in addition to, the normaltrichloropropane. To have hydroxyl terminals, the product is capped withethylene oxide. Furthermore. hydroxyl and carboxyl terminals may beformed as in U.S. Pat. No. 2,676,165.

The perfluoroalkyl iodides which are suitable for use in this inventioncorrespond to the general formula: C,,F ,l wherein n 2 to 30, preferablyn 2 to 20, and most preferably any single perfluoroalkyl iodide or anymixture thereof. These iodides may be prepared in any well known manner.Representative modes of preparation are illustrated in Fluorocarbons andtheir Derivatives" by R. E. Banks, London, 1964, p. 56-61; and in anarticle by l-lazeldine, J. Chem. Soc., London, 1953, p. 3761 which areincorporated herein by reference. These perfluoroalkyl iodides arecompletely fluorinated and contain no hydrogen or other substituentsalong the alkyl chain as evidenced by the alternative representationRf]. While individual iodides may be used, some advantages develop fromthe use of mixed allkyl groups, thereby making such a mixture suitablefor use in this invention.

The addition of the perfluoroalkyl iodides to the hydroxyl orcarboxyl-terminated polymer, having pendant vinyl or allyl groupswherein perfluoroalkyl iodide is reacted with at least some of thependant vinyl or allyl groups, may readily be performed by reactingperfluoroalkyl iodides with the desired polymer in the presence of afree-radical generating catalyst or ultraviolet light, at a temperatureof about 40-l50C., and either with or without solvent as disclosed in,and incorporated by reference herein, copending U.S. Ser. No. 259,650filed June 5, 1972.

The reaction products of this invention may be dehydroiodinated for themost part by reaction with an amine such as morpholine or a strong basesuch as sodium hydroxide or potassium hydroxide in a suitable mediumsuch as water or dioxane. The removal of the iodine produces a lesscorrosive product, which may be desirable, but is not necessary, toproduce the molds of this invention. The dehydroiodinated version ismeant to be encompassed within the meaning of the reactions of theperfluoroalkyl iodides and the hydroxyl or carboxyl-terminated polymersand copolymers.

The perfluoroalkyl iodide modified polymers with hydroxyl terminals arethen reactable with polyisocyanates to prepare urethane prepolymersusing conventional technology, or to be reacted with polyepoxides toform polyether again with conventional technology. Furthermore, thecarboxyl terminated modified polymers may be reacted with thepolyepoxides to form polyesters.

Examples of suitable organic polyisocyanates, which are reacted with theperfluoroalkyl iodide modified hydroxyl terminated polymers to form saidurethane prepolymers, include aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, pphenylenediisocyanate, 4,4'-diphenylmethane diisocyanate,3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4-diphenylenediisocyanate, l,5-naphthylene diisocyanate; aliphatic diisocyanates suchas trimethylene diisocyanate tetramethylene diisocyanate, adipyldiisocyanate, hexamethylene diisocyanate; aliphatic diisocyanatescontaining the aromatic ring such as pxylene diisocyanate, m-xylylenediisocyanate; cycloaliphatic diisocyanates such as methylene-bis-4,4'-cyclohexylisocyanate, isopropylidene-bis-4,4- cyclohexylisocyanate,cyclohexane 1,4-diisocyanate. Mixture of two or more of saidpolyisocyanates may also be used.

In addition to the simple polyisocyanates described above, thehydroxyl-terminated perfluoroalkyl iodide modified materials can becondensed with isocyanate polymers, such as polyarylene polyisocyanate(PAPI) and/or with isocyanate-terminated polyhydroxy materials, e.g.,polyesters, etc., which are generally produced by reacting theisocyanate with, for example, polyglycols (such as polypropylene glycol)and polyesters (for instance of glycols, including polyglycols andpolycarboxylic acids, such as polyethylene adipate These materials maybe reacted with an excess of a diisocyanate. An example of such amaterial is the product obtained by the reaction of one mole ofpropylene glycol with 2 moles of 2,4-tolylene diisocyanate as shownbelow:

As mentioned, polyisocyanates such as the materials sold commercially asPAPI (polyarylene polyisocyanate) of the following structure:

NCO

can also be employed. Other isocyanate reactants which can be utilizedin the manufacture of the products of the present invention areisocyanate terminated prepolymers prepared by the reaction of tolylenediisocyanates or other isocyanates with hydroxyl or amineterminatedpolyesters, polyethers, or polyamides so that the hydroxyl terminatedperfluoroalkyl iodide modified polymers disclosed herein act as chainextending or curing agents for the other polymers. The isocyanatematerials are often used in an amount sufficient to supply 0.1 to 10 NCOgroups per OH group of the intermediate polymer, preferably about 0.5 to5 isocyanate groups per hydroxyl. When simple diisocyanates are used, itis preferred to employ about 4l0 percent, say about 5-8 percentdiisocyanate by weight of the intermediate polymer, or otherhydroxylterminated polymer which enters the urethane reaction.

In view of the natural affinity of fluorocarbon compounds for oxygenfrom the air, skinning of the fluoromodified polymers is relativelyrapid. Accordingly any normal antioxidant may be used, such as aphenolic antioxidant like Plastanox 2246, or 4,4- methylene bis(2,6-di-tert-butylphenol) (Ethyl Corp. Antioxidant 702), or4,4'-methylene bis (6-tert-butylo-cresol) (Ethyl Corp. Antioxidant 720).

The NCO-terminated perfluoroalkyl iodide modified polymer is then curedto form a mold or a mold liner, or it is used as a casting composition.In all cases, the curing is in accord with normal urethane technology,i.e. both polyols and polyamines may be used either individually or inmixtures.

These prepolymers may be reacted with polyhydroxy materials such asglycols, including polyglycols, polyesters and further amounts ofhydroxyl-terminated polydiene, to give additional urethane linkages inthe finished polymer. When reacted with diamines, ureaurethane polymersare formed. Urea-urethane polymers also may be formed in a single stepby concurrent reactions among the perfluoroalkyl iodide modifiedpolymer, the polyisocyanate and the diamine.

A wide variety of aromatic and aliphatic diamines may be employed as areaction component to make the inherently mold releasable molds moldliners, or casting compositions of the present invention.

Typical amines of up to 40 or more carbon atoms which may be employedare aromatic diamines (both substituted and unsubstituted) such as4,4'-methylene bis (Z-chloroaniline) (MOCA), 3,3-dichlorobenzidine(DCB), N,N'-disecondarybutyl p-phenylene diamine, N,N'-dibenzylethylenediamine, methane diamine, ethylene diamine, ethanolamines,hydroxylamine, p,p'- idphenylamine, p-phenylene diphenylamine,hexamethylene diamine, diethylene triamine, tetraethylene pentamine,lauroguanamine, and amine-terminated products obtained from the reactionof dibasic acids with diamines. Diamides of similar carbon atom rangecan also be employed as chain extending agents; e.g., materials made bythe reaction of dibasic acids, acid chlorides or anhydrides withammonia.

Typical polyols which may be employed are such as polypropylene diol,oxypropylated ethylene diamine, ethylene glycol, catechol. oxypropylatedaniline, propylene glycol, diethylene glycol, triethylene glycol, thebutane diols, pentane diol, hexane diol, neopentyl glycol, triallyloxypentaerythritol, triallyloxy hexane tetrol, tetraallyloxy arabitol, andpentallyloxy dulcitol.

Alternatively, the perfluoroalkyl iodide modified hydroxyl terminatedpolymer can be used to cure other NCO-terminated prepolymers asindicated above, again by conventional urethane technology, to producethe molds, mold liners, or casting composition of this invention whichrequire no mold release agent when used.

Polyepoxide materials react with the abovedescribed hydroxyl or carboxylterminated perfluoroalkyliodide-modified polymers to form polyethers orpolyesters possessing the same mold release properties described. Thepolyepoxides are preferably liquids which have an average epoxidefunctionality of approximately two epoxide groups per molecule ofpolyepoxide material. The position of epoxide groups in the polyepoxidematerial is not critical to the practice of this invention. Forinstance, if the polyepoxide material is essentially linear in structureepoxide groups may be in terminal positions or they may be positionedintermediately and/or randomly along the linear structure. Polyepoxidematerials which may enter into cure with the above defined polymersinclude the following types of materials:

1. Essentially linear types such as and epoxidized polybutadienematerials such as those which have an epoxide functionality of four ormore and which are sold under the designation Oxiron resins, i.e.,Oxiron 2000, Oxiron 2001" and Oxiron 2002;

2. Epichlorohydrin-bisphenol A types which are aromatic in nature andwhich include those sold under the trademark designation Tipox, i.e.,Tipox A," Tipox B," and Tipox C, those sold under the designation Epon"resins, i.e., Epon 828 and Epon 820, those sold under the designationBakelite ERL" resins, and those sold under the designation Epi-Rez"resins, i.e., Epi-Rez 510;

3. C yclo-aliphatic types which include those sold under the designationUnox resins, i.e., Unox 206," which is epoxy ethyl-3,4-epoxy cyclohexaneand Unox 201 which is 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylcyclohexanecarboxylate;

4. Resorcinol diglycidyl ether types which include those sold under thedesignation Kopoxite resins, i.e., Kopoxite 159";

5. Epoxy novalak type which includes the resins sold under thedesignations Dow Epoxy Novalak 438" and DEN438-EK85, and also those soldunder the designation KER resins, i.e., KER 357A and KER 955A;

6. Epoxidized fatty acid resins including the Epoxol materials such asEpoxol 9-5; and others. In certain instances some solid polyepoxidematerials may be used, say where a finely distributed uniform dispersionwith liquid polymers may be obtained, or where the solid polyepoxidesare soluble in the polymer. Useful polyepoxide materials according tothe practice of this invention have epoxide equivalent weights of toover 4000. Thus within the requirements here taught a practitioner inthe art may choose from among a wide variety of polyepoxide materials asto specific epoxide equivalent values, specific molecular configuration,

' Quadrol molecular weight and functionality to pursue practice of thisinvention.

The fluorine content of any of the polymers is not critical but iscontrolled more for economic then technical reasons. Thus, the polymermay have a fluorine content of 1-40 percent preferably 3-25 percent, andmost preferably 6-15 percent. Of course, the higher tthe fluorinecontent, the more long lasting are the mold release properties.

The following examples are given to illustrate the practice of thepresent invention and are not intended to limit the scope thereof.

EXAMPLE I This example shows the detailed preparation of a moldrepresentative of this invention, and its subsequent testing.

A mixture of 250 g. of Poly BD R-45M resin (3 hydroxyl-terminatedpolybutadiene polymer from ARCO Chemical), 61.24 g. of perfluorodecyliodide (C F- l), g. benzoyl peroxide, and 200 mls. dioxane were placedin a reaction flask containing a stirrer and condenser. The reactionmixture was cloudy pink but turned clear amber during gradual heating90C. The reaction was kept at a slow reflux for hours and the progressthereof followed by vapor phase chromatographic analysis. When nounreacted C, F- l was presem, as shown by the chromatographic analysis,the solvent was removed by means of a vacuum evaporator with a waterbath at 40C. for 7 hours. The result was 237.1 g of perfluorodecyliodide modified hydroxylterminated polybutadiene polymer which had11.00% fluorine.

Conversion of the fluorinated, hydroxyl-terminated polymer to a urethaneprepolymer was achieved by further reaction of the resin with adiisocyanate (TDl). 33 g. of l-lylene TM (a mixture of 2,4 and 2,6tolylene diisocyanate) was added to the fluorinated resin of above andthe reactants were heated for 5 hours at 75-80C. to complete theprepolymer reaction. The prepolymer then had a 3.40% NCO and 10.26%fluorine content.

The above fluorinated urethane prepolymer was made into a mold whereinits mold release properties were tested. The mold was formulated from100 g. of the prepolymer from above, .25 g. Antifoam A, 2.87 g.

(N,N,N',N'-tetrakis (2-hydroxypropylethylene diamine), and 2.87 g.2-ethyl-l ,3-hexanediol. The Antifoam A was used as a degassing agent toproduce bubble free molds. After all of the ingredients were mixedtogether the composition was degassed in a heated desiccator undervacuum at 120F. for 5 minutes. The composition was then poured into amold with a pattern of the article to be later cast. The mold was thenallowed to cure for 16 hours at room temperature, whereupon the patternwas removed.

To test the mold release properties of the mold, a water filledpolyester resin was cast into the mold, cured at room temperature, andremoved. 100 g. Polylite polyester resin from Reichhold Chemical wasextended with 100 g. tap water with the water being added gradually withstirring until a uniform mixture was obtained. Just prior to eachcasting 3 parts/100 parts of water extended resin of methyl ethyl ketoneperoxide in butyl phthalate solution was added as curing agent. 50separate castings were made from the mold prepared as above and all ofthe castings were removed from the mold with no trouble whatsoever.

Also, all of the castings were extremely clear in detail.

EXAMPLE 11 EXAMPLE 111 The procedure of Example 11 was repeated exceptvarying the curative used in preparing the mold. The following curativeswere used in the amounts specified per 100 g. of fluorinated prepolymer:

a. lsonol 100 6.4 g.

Quadrol 1.12 g b. Triisopropanol Amine 5.36 g c. lsonol 100 7.04 gQuadrol 1.23 g d. Trimethylolpropanc 3.76 g e. lsonol 100 5.81 Quadrol1.02

In all of the curing formulations, the molds cured within 24 hours, andthey all showed their mold release properties when the VultafoamRUR-25l-1O was cast into them. lsonol 100 is N,N-bis (2-hydroxypropyl)aniline from Upjohn.

EXAMPLE IV This example shows the use of the fluorinated polyurethane asa mold liner for a polyurethane mold.

To prepare the mold, a composition like that of Example I, but with afluorine content of only 4.2 percent was degassed and poured into moldwith the pattern sought to be cast. This mold was allowed to stand atroom temperature for 2 hours at which time the mixture had gelled andwas in a tacky state. Next a strip of teflon was placed at one end, overthe tacky material, to prevent adhesion between the fluorinated urethaneprepolymer and the unfluorinated urethane at this point. The separationwas for testing the adhesion between the two materials, and would notnormally be there.

Next a mixture of Solithane -291, a polyester-based urethane prepolymerof Thiokol Chemical Corporation, and lsonol 93 curative from Upjohn wasprepared, degassed, and then poured into the mold over the fluorinatedcomposition. The mold was then allowed to cure for 24 hours at roomtemperature.

To determine the mold release properties of the mold which was linedwith the fluorinated material, an epoxy resin ERL-2795 from UnionCarbide was prepared and cast into the mold. More than 10 castings wereobtained with no apparent deterioration in the mold release properties.All of the castings were clear in detail and easily released from themold.

To test the adhesion between the fluorinated and non-fluorinatedpolyurethanes, the teflon strip was removed and the two materials werepulled apart. It was found that exceptional adhesion had formed, therebyshowing the use of the composition as a mold liner. Also, during theremoval of the above castings by flexing the mold, no separationoccurred between the fluorinated and non-fluorinated polyurethanes.

EXAMPLE V A mold requiring no mold release agent is prepared from apolysulfide-backboned-polymer by incorporating in the preparationthereof 2,3- dichloropropylallylether in place of the trichloropropaneand capping the mercaptan terminated polymer with ethylene oxide to givehydroxyl terminals. Thus a polysulfide polymer with hydroxyl terminalsand pendant allyl groups is prepared. The procedure of Example I inadding the perfluoroalkyl iodide, making the urethane prepolymer andmaking a mold therefrom is repeated. The prepolymer is made to have16.2% fluorme.

To test the mold release properties of the resultant mold. A polyestercasting resin, MR -37C produced by W. R. Grace & Co., is prepared andcast into the mold as described previously. Fifteen castings withexcellent reproduction of detail are obtained with no apparentdeterioration of the mold.

EXAMPLE VI A polyether mold requiring no mold release agent is preparedby reacting the hydroxyl-terminated fluorocarbon-containingpolybutadiene polymer of Example with a polyepoxy resin. The mold isformulated from 100 g. of the polymer of Example I, 50 g. of ERL- 2774(a bisphenol-A type epoxy resin from Union Carbide) g. 2,4,6-tri(dimethyl-amino methyl) phenol as a catalyst, and 0.5 g. Antifoam A. Amold is prepared from this formulation as described in Example I and themold release properties are tested with the Polylite water extendedpolyester resin. Over 35 separate castings are made and all of thecastings have a detailed and precise reproduction of the surface patternof the article being copied.

EXAMPLE VII This example shows the preparation of a polyester mold froma carboxyl-terminated polymer and a polyepoxide.

The procedure of Example I is repeated except that HC-434 (acarboxyl-terminated polybutadiene resin from Thiokol ChemicalCorporation) replaces the Poly BD R-45M and a polyepoxide is usedinstead of the I-Iylene TM. The mole is then prepared from 100 g. of the18.3% flourocarbon-containing carboxyl terminated polymer, g. ofERL-4239 from Union Carbide [bis (3,4-epoxy-6-methyl cyclohexyl methyl)adipate], 3 g. of stannous octoate catalyst, and 0.5 g. Antifoam Adegassing agent.

The resultant mold is tested using the Polylite water extended polyesterresin of Example I and more than castings are obtained all withexcellent reproduction of the surface characteristics of the articlebeing copied.

What is claimed is:

l. A mold, which requires no mold release agent, in which at least thesurface that contacts a casting composition comprises a curedfluorocarbon-containing polyester prepared from polyepoxides havingepoxide functionality of approximately two epoxide groups per moleculeand a carboxy terminated polymer; wherein said carboxy-terminatedpolymers contain pendant vinyl or allyl groups and wherein at least someof said pendant groups are converted to 2-perfluoroalkyl-l iodoethylgroups or 3 perfluoroalkyl-2-iodopropyl groups to provide a fluorinecontent of from 1 to percent.

2. The mold of claim 1 wherein the carboxyterminated polymers havingpendant vinyl or allyl groups are selected from the group consisting ofpolybutadiene polymers, polybutadiene copolymers, polyether polymers,polyester polymers, and polysulfide polymers.

3. The mold of claim 2 wherein the carboxyterminated polymers havingpendant vinyl or allyl groups are polybutadiene polymers.

4. The mold of claim 2 wherein the carboxyterminated polymers havingpendant vinyl or allyl groups are butadiene/styrene copolymers.

5. The mold of claim 1 wherein the cured fluorocarbon-containingpolyester polymer comprises the entire mold.

6. The mold of claim 1 wherein the cured fluorocarbon-containing polymerprior to curing contains 3-25 percent by weight fluorine.

7. The mold of claim I wherein the cured fluorocarbon-containing polymerprior to curing contains 6-15 percent by weight fluorine.

8. A fluorocarbon-containing polymer casting composition, which isinherently mold releasable. which comprises a polyester prepared frompolyepoxides having epoxide functionality of approximately two epoxidegroups per molecule and an carboxy terminated polymer, wherein saidcarboxy-terminated polymers contain pendant vinyl or allyl groups andwherein at least some of said pendant groups are converted to 2-perfluoroalkyl-l iodoethyl groups or 3-perfluoroalkyl- 2-iodopropylgroups to provide a fluorine content of from 1 to 40 percent.

9. The casting composition of claim 8 wherein the carboxy-terminatedpolymers having pendant vinyl or allyl groups are selected from thegroup consisting of polybutadiene polymers, polybutadiene copolymers,polyether polymers, polyester polymers, and polysulfide polymers.

10. The casting composition of claim 9 wherein the carboxy-terminatedpolymers having pendant vinyl or allyl groups are polybutadienepolymers.

11. The casting composition of claim 9 wherein the carboxy-terminatedpolymers having pendant vinyl or allyl groups are butadiene/sytrenecopolymers.

1. A MOLD, WHICH REQUIRES NO MOLD RELEASE AGENT, IN WHICH AT LEAST THESURFACE THAT CONTACTS A CASTING COMPOSITION COMPRISES A CUREDFLUOROCARBON-CONTAINING POLYESTER PREPARED FROM POLYEPOXIDES HAVINGEPOXIDE FUNCTIONALITY OF APPROXIMATELY TWO EPOXIDE GROUP PER MOLECULEAND A CARBOXY TERMINATED POLYMER; WHEREIN SAID CARBOXY-TERMINATEDPOLYMERS CONTAIN PENDANT VINYL OR ALLYL GROUPS AND WHEREIN AT LEAST SOMEOF SAID PENDANT GROUPS ARE CONVERTED TO 2PERFLUOROALKYL-1 -IODOETHYLGROUPS OR 3 : PERFLUOROALKYL-2IODOPROPYL GROUPS TO PROVIDE AFLUORINECONTENT OF FROM 1 TO 40 PERCENT.
 2. The mold of claim 1 wherein thecarboxy-terminated polymers having pendant vinyl or allyl groups areselected from the group consisting of polybutadiene polymers,polybutadiene copolymers, polyether polymers, polyester polymers, andpolysulfide polymers.
 3. The mold of claim 2 wherein thecarboxy-terminated polymers having pendant vinyl or allyl groups arepolybutadiene polymers.
 4. The mold of claim 2 wherein thecarboxy-terminated polymers having pendant vinyl or allyl groups arebutadiene/styrene copolymers.
 5. The mold of claim 1 wherein the curedfluorocarbon-containing polyester polymer comprises the entire mold. 6.The mold of claim 1 wherein the cured fluorocarbon-containing polymerprior to curing contains 3-25 percent by weight fluorine.
 7. The mold ofclaim 1 wherein the cured fluorocarbon-containing polymer prior tocuring contains 6-15 percent by weight fluorine.
 8. Afluorocarbon-containing polymer casting composition, which is inherentlymold releasable, which comprises a polyester prepared from polyepoxideshaving epoxide functionality of approximately two epoxide groups permolecule and an carboxy terminated polymer, wherein saidcarboxy-terminated polymers contain pendant vinyl or allyl groups andwherein at least some of said pendant groups are converted to2-perfluoroalkyl-1 iodoethyl groups or 3-perfluoroalkyl-2-iodopropylgroups to provide a fluorine content of from 1 to 40 percent.
 9. Thecasting composition of claim 8 wherein the carboxy-terminated polymershaving pendant vinyl or allyl groups are selected from the groupconsisting of polybutadiene polymers, polybutadiene copolymers,polyether polymers, polyester polymers, and polysulfide polymers. 10.The casting composition of claim 9 wherein the carboxy-terminatedpolymers having pendant vinyl or allyl groups are polybutadienepolymers.
 11. The casting composition of claim 9 wherein thecarboxy-terminated polymers having pendant vinyl or allyl groups arebutadiene/sytrene copolymers.